1// Copyright (c) 2011 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef BASE_TASK_QUEUE_H_
6#define BASE_TASK_QUEUE_H_
7#pragma once
8
9#include <deque>
10
11#include "base/base_api.h"
12#include "base/task.h"
13
14// A TaskQueue is a queue of tasks waiting to be run.  To run the tasks, call
15// the Run method.  A task queue is itself a Task so that it can be placed in a
16// message loop or another task queue.
17class BASE_API TaskQueue : public Task {
18 public:
19  TaskQueue();
20  ~TaskQueue();
21
22  // Push the specified task onto the queue.  When the queue is run, the tasks
23  // will be run in the order they are pushed.
24  //
25  // This method takes ownership of |task| and will delete task after it is run
26  // (or when the TaskQueue is destroyed, if we never got a chance to run it).
27  void Push(Task* task);
28
29  // Remove all tasks from the queue.  The tasks are deleted.
30  void Clear();
31
32  // Returns true if this queue contains no tasks.
33  bool IsEmpty() const;
34
35  // Run all the tasks in the queue.  New tasks pushed onto the queue during
36  // a run will be run next time |Run| is called.
37  virtual void Run();
38
39 private:
40   // The list of tasks we are waiting to run.
41   std::deque<Task*> queue_;
42};
43
44#endif  // BASE_TASK_QUEUE_H_
45